1128420 - Properly handle finished output streams in MediaDecoder

Status: RESOLVED FIXED

(Core :: Audio/Video, defect)

Description

[JW Wang [:jwwang] [:jw_wang]]

When we seek at a position near the end to a previous position, chances are the output stream is finished without MediaDecoder::PlaybackEnded being called. The finished stream is then re-connected to the decoded stream in MediaDecoder::RecreateDecodedStream() and block the decoded stream. Therefore, the captured media element wouldn't be able to play after seeking.

We need to ensure finished streams are removed from the output streams of MediaDecoder to avoid this problem.

Comment 1

[JW Wang [:jwwang] [:jw_wang]]

Attachment: 1128420_remove_finished_output_streams-v1.patch

Remove finished streams in a reliable way. See comment 0 for the detail.

Try: https://tbpl.mozilla.org/?tree=Try&rev=4d9432fb964e
Most green in 30 runs on most platforms.

Comment 2

[JW Wang [:jwwang] [:jw_wang]]

Comment on attachment 8561185 [details] [diff] [review]
1128420_remove_finished_output_streams-v1.patch

Review of attachment 8561185 [details] [diff] [review]:
-----------------------------------------------------------------

::: dom/media/MediaDecoder.cpp
@@ -944,5 @@
>        mPlayState == PLAY_STATE_LOADING) {
>      return;
>    }
>  
> -  {

OutputStreamListener is responsible for removing finished streams. We don't need this block in PlaybackEnded() anymore.

::: dom/media/MediaDecoder.h
@@ -496,4 @@
>      nsRefPtr<ProcessedMediaStream> mStream;
>      // mPort connects mDecodedStream->mStream to our mStream.
>      nsRefPtr<MediaInputPort> mPort;
> -    bool mFinishWhenEnded;

We don't need mFinishWhenEnded for OutputStreamListener will be responsible for removing finished streams.

Comment 3

[JW Wang [:jwwang] [:jw_wang]]

Try: https://tbpl.mozilla.org/?tree=Try&rev=4d9432fb964e
Most green in 30 runs on most platforms.

inbound: https://hg.mozilla.org/integration/mozilla-inbound/rev/0f4fc6a418ed

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/0f4fc6a418ed